With the high speed development of economy, influence of energy consumption and environmental pollution on people's life has been paid more and more attentions. Energy-saving and emission-reduction have become a social problem concerning national welfare and the people's livelihood. Scientific electricity utilization with the objects of rational and economical electricity utilization is one of the focuses of energy-saving and emission-reduction. Scientific electricity utilization is based upon timely and accurate acquisition of electricity utilization information, and energy consumption analysis and power usage management based on the electricity utilization information.
FIG. 1 shows a technical proposal for acquiring electricity utilization information. As shown in FIG. 1, an isolated power supply 110 is configured to convert an input AC power into a DC power to provide a suitable voltage VDD to a data acquisition and processing circuit 120, and to provide a suitable voltage VCC to a RS485 circuit 130. An isolated DC/DC circuit 150 provides electrical isolation for VDD and VCC. The value of voltage VDD is determined from the operation voltage of the data acquisition and processing circuit 120; and the value of voltage VCC is determined from the operation voltage of the RS485 circuit 130. The isolated power supply 110 generally includes an isolation transformer and a rectifying filtering circuit wherein the isolation transformer provides an electrical isolation. The data acquisition and processing circuit 120 is configured to detect an operation parameter of a power supply circuit 900. The operation parameter may include an operation current and an operation voltage, etc of the power supply circuit 900. An optical coupling component 140 located between the data acquisition and processing circuit 120 and the RS485 circuit 130 is configured to isolate signal transmission. The RS485 circuit 130 transmits the detected operation parameter to a remote server 190 via a RS485 bus. Generally, the isolated power supply 110, the data acquisition and processing circuit 120, the optical coupling component 140, the RS485 circuit 130 and the isolated DC/DC circuit 150 are enclosed in one measuring device 100 that is mounted in a distribution box for providing operation parameters of one power supply circuit 900 to the remote server 190. A power supply circuit generally includes a plurality of power supply sub-circuits. For example, a power supply circuit may include a plurality of power supply sub-circuits such as an illumination circuit, a receptacle circuit and an air conditioning circuit.
In practical applications, one electric energy meter is provided for each power supply circuit (such as the power supply circuit corresponding to the above-mentioned measuring device 100) to measure the consumed electrical energy. However, users, especially those consuming energy heavily in civil buildings such as state organs' office buildings and large size public buildings, can not find possible energy-saving links with a definite object in view since they use one electric energy meter for providing overall electricity utilization information of the power supply circuit.
In order to analyze energy consumption more accurately, it is desired to be able to monitor energy consumption of individual power supply sub-circuits at the same time, that is, to implement divided measurement or sub-metering of electricity utilization. It has been proposed to implement divided measurement of electricity utilization of each power supply sub-circuit by the measuring device 100 shown in FIG. 1. However, since the isolated power supply 110 has a large volume, and the isolated DC/DC circuit 150 and the optical coupling component 140 are required for the RS485 circuit 130, the detection device 100 is bulky. If a plurality of the measuring devices 100 are used to monitor a plurality of power supply sub-circuits, a large space will be occupied. Therefore, this proposed solution is difficult to be applied in practice.